[Nexus 4 Q&A, Help & Troubleshooting] cb474:
I've been agonzing over this decision also, between the Nexus 4 and the North American One X+.

One thing that I do not think has been mentioned in this thread is that the One X+ has a much better camera than the Nexus 4. I'm speaking in terms of the actual hardware of the camera and the image quality that it produces. The Nexus 4 camera has been consistently reviewed as being very middle of the road, for this level of device (by reviewers who are serious about cameras and are more thorough than simply offering their subjective opinion). Really, none of the Nexus devices have had a flagship worthy camera. Sometimes there are some clever software innovations. But the sensor quality has always been lacking in Nexus devices and behind the times, compared to their contemporaneous flagship rivals. In contrast, the One X+ has a F2.0 28 mm sensor that offers good low light performance and overall superior image quality. So if that's something you care about, it could be worth consideration.

In principle, I'd prefer a Nexus device for the open platform and all the development on it. In practice, the 16 GB max storage has given me pause, as well as worries that the device will be fragile, due to the glass back, and the middle of the road camera. I'm not so concerned about the lack of LTE. I do really find the softkeys to be a complete waste of screen space on the Nexus 4. The One X+ is exactly the same size device, with the same size screen, and manages to fit in capacitive keys. It's a much better way to preserve precious screen space.

I like the design of the One X+ body better, both aesthetically, the way it feels in the hand, and because I think it will be more durable. The polycarbonate really is nice. And despite other comments here, I think HTC actually has very good hardware designs and the One X+ is one of their nicest designs in a while. Obviously the 64 GB of storage on the One X+ is great and of course there's the camera. But I really hesitate to get a One X+ due to the relative lack of development on the North American version. It looks like finally there will be good work on Cyanogen. But I do worry that as soon as the M7 comes along, the One X+ is going to be left behind. And HTC's apparent increasing hostility to development on its phones does not seem like a good omen either.

A feature I do care a lot about in any phone is the actually audio quality in calls, both in the earpiece and the quality that my caller hears on the other end of the line. I made some test calls (leaving messages to myself) in the AT&T store and T-Mobile store, to try both devices. Also, AnandTech has some nice recordings demonstrating how the noise cancellation works on both phones, One X: http://www.anandtech.com/show/5779/htc-one-x-for-att-review/7 Nexus 4: http://www.anandtech.com/show/6440/google-nexus-4-review/9

In then end, it seems to me like the Nexus 4 edges out the One X+ for audio quality in calls. Voices over the earpiece and for the caller at the other end of the line, I think, sound more natural on the Nexus 4. The One X+ has a bit of an overly processed and muffled quality, due I think to the noise cancellation. Perhaps this is because the One X+ has more powerful noise cancellation, using the Audience chip. It was hard for me to really tell if the Nexus 4 had equivalently effective noise cancellation in truly noisy environments. I know my Nexus One, also with the Audience chip, always performed very well in even extremely loud settings, but it has has the muffled and overly processed audio quality for my caller, which people have complained about over the years. Curiously, the Optimus G at the AT&T store seemed to have clearly better call quality than the Nexus 4, in terms of the naturalness of the voice both in the earpiece and for the caller at the other end of the line. I would have expected the Nexus 4 and Optimus G to be the same, due to their shared hardware.

In the end, with the Nexus 4 up for sale again, I decided to order one. It's hard to beat the price. And I think I'm just not going to be happy with the level of development on the North American One X+, especially in the long run. I don't want to have to put up with Sense at all, while waiting for Cyanogen. And I'd like the option of trying out some of the other interesting ROMs, like Paranoid Android, which I don't know if it will ever hit the One X+. I also find the whole S-Off situation on the One X+ annoying, even if it's just an inconvenience. I tend to keep a device for a couple years, so having ongoing development options is important to me. Perhaps if I got a new phone every year I wouldn't care as much.